Hello all,

 

Many thanks to all who responded to my troubles re the above.

 

When my son and colleagues arrived for work ( They run an on line retail business)  this morning and read the deluge of e mails they shut all systems down and we turned off the mains power supply. Fed underground.

The phone lines are also fed underground but fixed about 25cms above ground for about 25m to the input socket.

Using the main transmit antenna, 14mm top loaded vertical, and using a battery operated receiver the noise had disappeared completely. GI4DPE’s beacon was S7. Only just detected it previously.

 

I thought  we had been through this procedure before but with old age and failing memory I now recall this was done in relation to 80 m noise some time ago.

Switching power back on we then went through the laborious process of shutting down the large amount of equipment—Server and network systems and numerous PC terminals printers etc.

2 devices are causing the problem.

 

Firstly-fairly minor, a power supply to an HP 750 printer. Produces a carrier across the band.

 

Secondly-- an internal telephone system. 20 line - 4 in use, Panasonic KXT 61610BE—“ Electronic Modular Switching System”

The reason I associated the interference with broad band adsl was that using a portable RX placed anywhere near the telephone line produced massive QRN, even to the extent that I could detect it under ground.

I can only conclude that somehow this wonderful Electronic Modular Switching System is feeding back down the phone lines. I am not knowledgeable enough to know if this is possible but it certainly seems the case.

 

I am greatly indebted  to all who offered solutions and secured the co operation of “ workers” this end.

 

I just hope some other gremlin does not appear again

 

73s

 

Mike   GW4HXO.

 

PS Anyone know of an internal phone system –QRM free ? or a possible filter solution ?